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Related papers: Coherence Factors Beyond the BCS Result

200 papers

The phenomenon of low-temperature superconductivity is intimately associated with the condensation of weakly bound, very extended, strongly overlapping Cooper pairs, and systematic experimental studies of the associated mean square radius…

Nuclear Theory · Physics 2022-03-02 R. A. Broglia , F. Barranco , G. Potel , E. Vigezzi

We develop a concise self-consistent perturbation expansion for superconductivity where all the pair processes are naturally incorporated without drawing "anomalous" Feynman diagrams. This simplification results from introducing an…

Superconductivity · Physics 2011-11-16 Takafumi Kita

Using the standard Hamiltonian of the BCS theory, we show that in an ensemble of interacting fermions there exists a coherent state $|NC>$, which nullifies the Hamiltonian of the interparticle interaction. This state has an analogy with the…

Quantum Physics · Physics 2016-09-08 A. V. Taichenachev , V. I. Yudin

Lanthanum hydride is the superconductor with the highest known critical temperature. It is believed that the superconductivity is of standard BCS-type, with electrons forming Cooper pairs and opening the superconducting band gap. Here we…

Superconductivity · Physics 2023-03-09 Sebastiaan van de Bund , Graeme J. Ackland

The standard phenomenological Hamiltonian of a small superconducting Josephson junction in the charge regime (Cooper Pair Box) produces a model of the effective charge qubit with possible applications to quantum information processing. In…

Quantum Physics · Physics 2010-04-29 Robert Alicki

We study the coherence properties of a trapped two-component gas of fermionic atoms below the BCS critical temperature. We propose an optical method to investigate the Cooper-pair coherence across different regions of the superfluid.…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Gh. -S. Paraoanu , M. Rodriguez , P. Torma

The Bardeen-Cooper-Schrieffer (BCS)-Bose-Einstein condensation (BEC) crossover in the two-dimensional attractive Hubbard model under the magnetic field is discussed at the half-filling at T=0 K on the basis of the formalism of Eagles and…

Superconductivity · Physics 2015-06-23 Atsushi Tsuruta , Satoshi Hyodo , Kazumasa Miyake

We explore methods to generate quantum coherence through unitary evolutions, by introducing and studying the coherence generating capacity of Hamiltonians. This quantity is defined as the maximum derivative of coherence that can be achieved…

Quantum Physics · Physics 2024-08-13 Manfredi Scalici , Moein Naseri , Alexander Streltsov

We report on a fully self-consistent determination of a phase transition to a superconducting state in a conserving approximation. The transition temperature calculated for a two-dimensional Hubbard model with an attractive interaction in…

Superconductivity · Physics 2009-10-30 J. J. Deisz , D. W. Hess , J. W. Serene

The quantum dynamics of quasi-one-dimensional ring with varying electron filling factor is investigated in presence of external electric field. The system is modeled within Hubbard Hamiltonian with attractive Coulomb correlation, which…

Superconductivity · Physics 2016-04-21 Bradraj Pandey , Sudipta Dutta , Swapan K. Pati

Theoretical work has shed light on the phase behavior of idealized mixtures of many components with random interactions. But typical mixtures interact through particular physical features, leading to a structured, non-random interaction…

Statistical Mechanics · Physics 2022-09-05 Isabella R. Graf , Benjamin B. Machta

We examine the weakly interacting atoms in an ultracold Fermi gas leading to a state of macroscopic coherence, from a theoretical perspective. It has been shown that this state can be described as a fermionic coherent state. These coherent…

Quantum Physics · Physics 2013-04-05 Arnab Ghosh , Sudarson Sekhar Sinha , Deb Shankar Ray

Superfluidity or superconductivity with mismatched Fermi momenta appears in many systems such as charge neutral dense quark matter, asymmetric nuclear matter, and in imbalanced cold atomic gases. The mismatch plays the role of breaking the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Mei Huang

In the spirit of some earlier work on the construction of vector coherent states over matrix domains, we compute here such states associated to some physical Hamiltonians. In particular, we construct vector coherent states of the…

Quantum Physics · Physics 2009-11-10 S. Twareque Ali , F. Bagarello

A "super-atom" conceptual interface between chemistry and physics is proposed in order to assist in the search for higher TC superconductors. High-TC superconductivity HTSC is articulated as the entanglement of two disjoint electronic…

Superconductivity · Physics 2015-06-03 Itai Panas

A characteristic feature of the BCS theory of superconductivity is the quantum-mechanical coherence of particle and hole states. Direct observation of particle-hole coherence in unusual superconducting materials is a strong indication of…

Superconductivity · Physics 2010-11-16 D. Rainer , H. Burkhardt , M. Fogelstrom , J. A. Sauls

Understanding the nature of Cooper pairs is essential to describe the properties of superconductors. The original proposal of Bardeen, Cooper, and Schrieffer (BCS) was based on electrons pairing with same energy and zero center-of-mass…

Superconductivity · Physics 2023-01-11 Debmalya Chakraborty , Annica M. Black-Schaffer

The BCS-BEC crossover in a lattice is a powerful paradigm to understand how a superconductor deviates from the Bardeen-Cooper-Schrieffer physics as the attractive interaction increases. Optical lattices loaded with binary mixtures of cold…

Strongly Correlated Electrons · Physics 2014-05-15 A. Amaricci , A. Privitera , M. Capone

I consider relaxation of the pairing amplitude in a disordered Bardeen-Cooper-Schrieffer (BCS) superconductor in the absence of the two-particle collisions. My main assumption is that nonmagnetic and magnetic disorder scattering rates are…

Superconductivity · Physics 2024-03-11 Maxim Dzero

We present the Ramsey response and radio-frequency spectroscopy of a heavy impurity immersed in an interacting Fermi superfluid, using exact functional determinant approach. We describe the Fermi superfluid through the conventional…

Quantum Gases · Physics 2022-07-22 Jia Wang , Xia-Ji Liu , Hui Hu